User Manual - twentynine
Example 1
Figure 47 illustrates the packet resend mechanism with the following assumptions:
•
Packet
1007
is missing within the stream of packets and has not been recovered
•
MaxResendPacketRetry
parameter is set to 2
1003
1001
1000
999
1009
1008
1006
1004
1002
1005
1010 1011 1012 1013 1014
Time
(3)
(5)
(7)
1018
1017
1016
1015
1019 1020
(4)
(2)
(1)
(8)
(6)
Figure 47: Packet Resend example when MaxResendPacketRetry value has exceeded
Corresponding to Figure 47, the workflow of the Packet Resent mechanism would look like described below:
1. Stream of packets. Gray indicates packets that have been checked by the driver, white packets have
not yet been checked.
2. As packet
1008
is received, packet
1007
is detected as missing.
3. Interval defined by the
PacketResendTimeout
parameter.
4. The
PacketResendTimeout
is expired, the first resend request for packet
1007
is sent to the camera.
The camera does not respond with a resend.
5. Interval defined by the
PacketResendResponseTimeout
parameter.
6. The
PacketResendResponseTimeout
expires and second resend request for packet
1007
is sent to
the camera. The camera does not respond with a resend.
7. Interval defined by the
PacketResendResponseTimeout
parameter.
8. As the maximum number of resend requests has been sent (
MaxResendPacketRetry
) and the last
PacketResendResponseTimeout
has expired, packet 1007 is now considered as lost.
If a group of packets is missing (for example
1000, 1001, 1002 and 1003
), only one resend request will be
sent covering all connected packets.
69
SMARTEK Vision | User Manual - twentynine | Doc. v1.0.2